Preparation method and application of temperature-sensing hole-cutting liquid surface layer material

Abstract

The invention relates to the technical field of composite materials, in particular to a preparation method and application of a warm-heat-sensing hole cutting liquid surface layer material. The material comprises a non-woven fabric substrate and a nano non-woven fabric which is sprayed on the non-woven fabric substrate and contains a warming agent clathrate compound and soft components, the material is subjected to hydrophobic after-treatment and fine hole cutting treatment, and the material has warm feeling, softness, water resistance, high fluid absorption efficiency and biodegradability, can be applied to the fields of high-end hygienic products, medical treatment, clothing, air filtration and the like, and is wide in application prospect.

Description

Technical Field

[0001] The invention relates to the technical field of composite materials, in particular to a preparation method and application of a warm and hot cutting hole liquid surface layer material. Background Art

[0002] Polyurethane composites are widely used in the preparation of daily necessities, but traditional methods make it difficult to improve their spinnability under certain functional requirements. There are deficiencies in imparting specific functions (such as a warm feeling) and optimizing material properties (such as softness, water resistance, fluid absorption efficiency, etc.), especially when used as skin-friendly layer materials.

[0003] For example, Chinese invention patent application publication number CN1445390A discloses a method and apparatus for producing polyurethane elastic nonwoven fabrics by melt-blowing. Polyurethane particles are fed into a screw extruder, heated and melted at 180-260°C, and then extruded from spinnerets in a die head. Hot air flows from both sides of the spinnerets stretch the melt into ultrafine fibers, which then self-bond to form the polyurethane elastic nonwoven fabric of the present invention. This product offers excellent softness and comfort, but its functionality is limited, resulting in a poor user experience.

[0004] Therefore, the existing technology for the above problems still needs to be improved and developed. Summary of the Invention

[0005] The present invention aims to address the shortcomings of existing technologies by providing a method for preparing a thermally sensitive liquid surface material and its application. This thermally sensitive liquid surface material exhibits excellent thermal effects, a soft feel, water resistance, high fluid absorption efficiency, and biodegradability, resolving the functional deficiencies of conventional surface materials.

[0006] In order to achieve the above object, the present invention is implemented through the following technical solutions: The present invention provides a method for thermally cutting a hole in a liquid surface layer material, comprising the following steps: S1. Weigh a certain amount of polyurethane and dissolve it in an organic solvent to prepare a polyurethane solution; S2. The polyurethane solution obtained in step S1 and the emulsifier are added to an emulsifier and sheared at high speed to obtain a polyurethane emulsion; S3. A warming agent was prepared by inclusion of an inclusion agent to obtain a warming agent inclusion compound; S4. The warming agent inclusion compound prepared in step S3 is added together with the softener to the polyurethane emulsion prepared in step S2 and stirred thoroughly to obtain a uniform dispersion to obtain a mixed emulsion; S5. The mixed emulsion obtained in step S4 is sprayed on the surface of the non-woven fabric to obtain a nanofiber non-woven composite material; S6. The nanofiber nonwoven composite material is immersed in a hydrophobic finishing agent solution, fully impregnated, and then the excess solution is removed by roller extrusion and dried to obtain a hydrophobically modified nanofiber nonwoven composite material; S7. Cut holes in the hydrophobically modified nanofiber non-woven fabric composite material obtained in step S6 to obtain a warm-sensing hole-cut liquid surface layer material.

[0007] According to the above scheme, the concentration of the polyurethane solution prepared in step S1 is 150-250 mg / ml.

[0008] According to the above scheme, the emulsifier in step S2 is selected from one of a nonionic emulsifier or a cationic emulsifier, the weight ratio of the polyurethane solution to the emulsifier is 100:5-100:10, the high-speed shearing is 1200 revolutions per minute, and the shearing time is 30-45 minutes.

[0009] According to the above scheme, the warming agent in step S3 is one of vanillyl ether compounds, amide compounds, vanillin acetal, gingerol or nicotinic acid tocopherol, the inclusion compound is one of cyclodextrin or cyclodextrin derivatives or chitosan, the weight ratio of the warming agent to the cyclodextrin or cyclodextrin derivative inclusion agent is 1:1-1:8, and the weight ratio of the warming agent to the chitosan inclusion agent is 1:1-1:3.

[0010] According to the above scheme, the chitosan inclusion agent is modified chitosan, and the preparation method of the warming agent inclusion compound is: dissolving ethylene glycol chitosan in acetate buffer (pH=6), adding acetic anhydride for N-acetylation reaction, controlling the molar ratio of acetic anhydride to ethylene glycol chitosan amino groups to be 1.5:1-2.0:1 to obtain a modified chitosan solution, mixing the warming agent and the modified chitosan solution, using 300W power ultrasonic dispersion for 10 minutes, and heating to 37°C to obtain a warming agent inclusion compound.

[0011] According to the above scheme, the weight ratio of the polyurethane emulsified solution prepared in step S2 to the warming agent inclusion compound and the softener prepared in step S3 is 100:20-30:10.

[0012] According to the above scheme, the mixed emulsion in step S5 is sprayed using an emulsion electrospinning device, the electrospinning voltage is 15-20kV, the flow rate is 0.5-1.5mL / h, and the receiving distance is 15-20cm.

[0013] According to the above scheme, the hydrophobic finishing agent in step S6 is one or more of amino silicone oil, hydroxyl-terminated polysiloxane, alkoxysilane, C6 short-chain fluoride, fluorine-free water-repellent finishing agent, calcium stearate, stearic acid amide, acrylate copolymer, polyurethane-organic silicon block copolymer, organosilicon-fluorocarbon composite finishing agent, and nano-silica composite finishing agent. The mass-volume concentration of the hydrophobic finishing agent solution is 6.0-8.0 g / L, the immersion time is 0.1-5 min, and after sufficient immersion, the nanofiber non-woven fabric composite material after removing excess solution by a pressing roller is dried at 80-150°C for 10-15 min to obtain a hydrophobically modified nanofiber non-woven fabric composite material.

[0014] According to the above scheme, the perforation cutting process in step S7 is one of laser perforation, mechanical perforation, or ultrasonic perforation, precisely cutting regular holes into the hydrophobically modified nanofiber nonwoven composite material. The preset cutting parameters are: a patterned hole pattern, a hole diameter of 1mm-8mm, and a hole spacing of 3-16mm. According to the above scheme, the thermal perforated liquid surface layer material is used in sanitary products such as sanitary napkins, menstrual pants, incontinence pads, incontinence pants, diapers, disposable underwear, and wound dressings. The beneficial effects of the present invention are: (1) The present invention significantly improves the spinnability of polyurethane by constructing an emulsion system. Using the emulsified polyurethane solution as the raw material, the diameter, porosity and other parameters of the fiber can be precisely adjusted to meet the needs of different application scenarios.

[0015] (2) The present invention uses modified chitosan to prepare an inclusion compound for the warming agent, which has a highly porous structure with interconnected pores, and can continuously release the warming agent, bringing a gentle and comfortable warm feeling to the user.

[0016] (3) The present invention performs hydrophobic finishing on the nanofiber nonwoven fabric composite material to form an extremely low surface energy molecular layer on its surface, which effectively blocks water penetration, improves water resistance, and reduces liquid surface residue.

[0017] (4) The present invention uses a large number of tiny holes constructed by fine-cutting the nanofiber non-woven fabric composite material, which greatly increases the liquid infiltration rate. It can quickly absorb liquid and promote diffusion in the fields of sanitary products, medical wound dressings, etc., and the structure of the non-woven fabric also helps liquid conduction, further improving the absorption efficiency.

[0018] (5) The present invention reasonably selects polyurethane raw materials and additives to prepare a cutting liquid surface material that is biodegradable and meets environmental protection requirements. DETAILED DESCRIPTION

[0019] In order to better understand the present invention, the content of the present invention is further illustrated below in conjunction with examples, but the present invention is not limited to the following examples. Example

[0020] This embodiment provides a method for preparing a liquid surface layer material for a thermally sensitive cutting hole: S1. Weigh 15 g of polyurethane and dissolve it in 100 ml of N,N-dimethylformamide to prepare a polyurethane solution with a concentration of 150 mg / ml.

[0021] S2. 100 parts by weight of the polyurethane solution obtained in step S1 and 5 parts by weight of a nonionic emulsifier polyoxy-10-nonyl ether were added to an emulsifier, and high-speed shearing was performed at 1200 revolutions per minute for 30 minutes to obtain a polyurethane emulsion.

[0022] S3. Take 1 part by weight of the warming agent gingerol and 1 part by weight of the cyclodextrin inclusion agent, place the cyclodextrin in a reactor and heat it to above 50°C to prepare a saturated aqueous solution, dissolve the warming agent in an organic solvent to prepare a warming agent solution, slowly add the warming agent solution to the reactor, continue heating and stirring for 5 hours, filter while hot or filter after cooling and standing, and obtain the inclusion compound after drying.

[0023] S4. The polyurethane emulsified solution prepared in step S2 and the warming agent inclusion compound and softener prepared in step 3 are added to the polyurethane emulsion prepared in step S2 in a weight ratio of 100:20:10, and stirred thoroughly to uniformly disperse them to obtain a mixed emulsion.

[0024] S5. The mixed emulsion prepared in step S4 was sprayed onto the surface of a polypropylene hot air nonwoven fabric with a total weight of 20 g / m² using an emulsion electrospinning device at an electrospinning voltage of 15 kV, a flow rate of 0.5 mL / h, and a receiving distance of 15 cm to prepare a nanofiber nonwoven fabric composite material.

[0025] S6. Immerse the nanofiber nonwoven fabric composite material obtained in step S5 in an amino silicone oil solution with a mass-volume concentration of 6.0 g / L for 0.1 min. After sufficient immersion, remove excess solution from the nanofiber nonwoven fabric composite material by squeezing with a roller and dry it at 80°C for 10 min to obtain a hydrophobically modified nanofiber nonwoven fabric composite material.

[0026] S7. The hydrophobically modified nanofiber nonwoven composite material obtained in step S6 is cut into holes using ultrasonic waves, with preset cutting parameters as follows: a circular hole shape, a hole diameter of 1 mm, and a hole spacing of 3 mm. Example

[0027] This embodiment provides a method for preparing a liquid surface layer material for a thermally sensitive cutting hole: S1. Weigh 20 g of polyurethane and dissolve it in 100 ml of N,N-dimethylformamide to prepare a polyurethane solution with a concentration of 200 mg / ml.

[0028] S2. 100 parts by weight of the polyurethane solution obtained in step S1 and 5 parts by weight of a cationic emulsifier, cetyltrimethylammonium bromide, were added to an emulsifying vessel and sheared at 1200 rpm for 30 minutes to obtain a polyurethane emulsion.

[0029] S3. Take 1 part by weight of the warming agent vanillyl butyl ether and 5 parts by weight of the cyclodextrin derivative inclusion agent, place the cyclodextrin derivative in a reactor and heat it to above 50°C to prepare a saturated aqueous solution, dissolve the warming agent in an organic solvent to prepare a warming agent solution, slowly add the warming agent solution to the reactor, continue heating and stirring for 10 hours, filter while hot or filter after cooling and standing, and obtain the inclusion compound after drying.

[0030] S4. The polyurethane emulsified solution prepared in step S2 and the warming agent inclusion compound and softener prepared in step 3 are added to the polyurethane emulsion prepared in step S2 in a weight ratio of 100:25:10, and stirred thoroughly to uniformly disperse them to obtain a mixed emulsion.

[0031] S5. The mixed emulsion obtained in step S4 was sprayed onto the surface of a polypropylene spunbond nonwoven fabric having a gram weight of 30 g / m² using an emulsion electrospinning device at an electrospinning voltage of 17.5 kV, a flow rate of 1 mL / h, and a receiving distance of 17.5 cm to obtain a nanofiber nonwoven composite material.

[0032] S6. Immerse the nanofiber nonwoven fabric composite material obtained in step S5 in a stearic acid amide solution with a mass-volume concentration of 7.0 g / L for 3 minutes. After sufficient immersion, remove excess solution from the nanofiber nonwoven fabric composite material by a pressing roller and dry it at 115°C for 12.5 minutes to obtain a hydrophobically modified nanofiber nonwoven fabric composite material.

[0033] S7. The hydrophobically modified nanofiber nonwoven composite material obtained in step S6 is mechanically cut using a CNC blade cutting device, with the preset cutting parameters being: a hexagonal hole shape, a hole diameter of 4.5 mm, and a hole spacing of 9.5 mm, where the hole diameter is the distance between each two opposite endpoints of the six endpoints of the hexagon. Example

[0034] This embodiment provides a method for preparing a liquid surface layer material for a thermally sensitive cutting hole: S1. Weigh 20 g of polyurethane and dissolve it in 100 ml of N,N-dimethylformamide to prepare a polyurethane solution with a concentration of 200 mg / ml.

[0035] S2. 100 parts by weight of the polyurethane solution obtained in step S1 and 7.5 parts by weight of a cationic emulsifier cetyltrimethylammonium bromide were added to an emulsifying vessel and sheared at 1200 rpm for 37.5 minutes to obtain a polyurethane emulsion.

[0036] S3. Dissolve ethylene glycol chitosan in acetic acid buffer (pH = 6), add acetic anhydride for N-acetylation reaction, and control the molar ratio of acetic anhydride to ethylene glycol chitosan amino groups to be 1.5:1 to obtain a modified chitosan solution. Then, mix the warming agent vanillyl butyl ether and the modified chitosan solution at a mixing ratio of 1:1 by mass, use 300 W power ultrasonic dispersion for 10 minutes, and raise the temperature to 37°C to obtain a warming agent inclusion complex.

[0037] S4. The polyurethane emulsified solution obtained in step S2, the warming agent inclusion compound obtained in step S3, and the softener are added to the reactor in a weight ratio of 100:25:10, and stirred thoroughly to uniformly disperse them to obtain a mixed emulsion.

[0038] S5. The mixed emulsion obtained in step S4 was sprayed onto the surface of a polypropylene spunbond nonwoven fabric having a gram weight of 30 g / m² using an emulsion electrospinning device at an electrospinning voltage of 17.5 kV, a flow rate of 1 mL / h, and a receiving distance of 17.5 cm to obtain a nanofiber nonwoven composite material.

[0039] S6. Immerse the nanofiber nonwoven fabric composite material obtained in step S5 in a stearic acid amide solution with a mass-volume concentration of 7.0 g / L for 3 minutes. After sufficient immersion, remove excess solution from the nanofiber nonwoven fabric composite material by a pressing roller and dry it at 115°C for 12.5 minutes to obtain a hydrophobically modified nanofiber nonwoven fabric composite material.

[0040] S7. The hydrophobically modified nanofiber nonwoven composite material obtained in step S6 is mechanically cut using a CNC blade cutting device, with the preset cutting parameters being: a hexagonal hole shape, a hole diameter of 4.5 mm, and a hole spacing of 9.5 mm, where the hole diameter is the distance between each two opposite endpoints of the six endpoints of the hexagon. Example

[0041] This embodiment provides a method for preparing a liquid surface layer material for a thermally sensitive cutting hole: S1. Weigh 25 g of polyurethane and dissolve it in 100 ml of N,N-dimethylformamide to prepare a polyurethane solution with a concentration of 250 mg / ml.

[0042] S2. 100 parts by weight of the polyurethane solution obtained in step S1 and 10 parts by weight of a cationic emulsifier, cetyltrimethylammonium bromide, were added to an emulsifying vessel and sheared at 1200 rpm for 45 minutes to obtain a polyurethane emulsion.

[0043] S3. Dissolve ethylene glycol chitosan in acetic acid buffer (pH = 6), add acetic anhydride for N-acetylation reaction, and control the molar ratio of acetic anhydride to ethylene glycol chitosan amino groups to be 2:1 to obtain a modified chitosan solution; then mix the warming agent trans-8-methyl-N-vanillyl-6-nonenamide with the modified chitosan solution at a mass ratio of 1:3, use 300 W power ultrasonic dispersion for 10 min, and raise the temperature to 37°C to obtain a warming agent inclusion complex.

[0044] S4. The polyurethane emulsified solution obtained in step S2 and the warming agent inclusion compound and softener obtained in step S3 are added to the reactor in a weight ratio of 100:30:10, and stirred thoroughly to uniformly disperse them to obtain a mixed emulsion.

[0045] S5. The mixed emulsion prepared in step S4 was sprayed onto the surface of a 100% pure polyester spunlace nonwoven fabric with a weight of 40 g / m² using an emulsion electrospinning device at an electrospinning voltage of 20 kV, a flow rate of 1.5 mL / h, and a receiving distance of 20 cm to produce a nanofiber nonwoven composite material.

[0046] S6. Immerse the nanofiber nonwoven fabric composite material obtained in step S5 in an acrylic ester copolymer solution with a mass-volume concentration of 8.0 g / L for 5 minutes. After sufficient immersion, remove excess solution from the nanofiber nonwoven fabric composite material by a pressing roller and dry it at 150°C for 15 minutes to obtain a hydrophobically modified nanofiber nonwoven fabric composite material.

[0047] S7. The hydrophobically modified nanofiber nonwoven composite material obtained in step S6 is cut using a laser, with preset cutting parameters as follows: a square hole shape, an 8 mm hole diameter, and a 16 mm hole spacing, where the hole diameter is the distance between each two opposite ends of the four end points of the square.

[0048] Comparative Example 1 The steps and process parameters are basically the same as those in Example 3, except that the warming agent inclusion compound in step 3 is not prepared.

[0049] Comparative Example 2 The steps and process parameters are basically the same as those in Example 3, except that the nanofiber nonwoven fabric composite material prepared in step S5 is not immersed in a fluorine-containing hydrophobic finishing agent solution for treatment.

[0050] Comparative Example 3 The steps and process parameters are basically the same as those in Example 3, except that the nanofiber non-woven fabric composite material prepared in step S6 is not subjected to the hole cutting process. The liquid surface layer materials prepared in Examples 1-4 and Comparative Examples 1-3 were subjected to physical property tests of warmth sensation, absorption rate and reverse osmosis value. The test methods and test data are as follows: 1) Warmth Sensation Test: Five women aged 25-35 were selected from each experimental group. They were asked to use products made with this material and experience the duration and intensity of the warm sensation. The intensity of the warm sensation was divided into five levels (level 1: none, level 2: weak, level 3: moderate, level 4: strong, and level 5: strong). 3) Absorption rate test: Use a pipette to draw 5 ml of test liquid and inject it into the center of the test sample. Start timing at the same time and record the time it takes for the liquid to disappear. 4) Reverse Osmosis Test: Pipette 5 ml of test liquid into the center of the test sample and let it sit for five minutes. Then, place a piece of filter paper in the center of the test sample and press the filter paper with a 2.5 kg weight for two minutes. Repeat three times and add the three weight increases to obtain the reverse osmosis value.

[0051] Table 1 Sample Warmth Warm duration (h) Absorption rate / s Reverse osmosis value / g Example 1 4 3 7 0.07 Example 2 3 3 5 0.05 Example 3 3 4 5 0.05 Example 4 3 3.5 3 0.03 Comparative Example 1 1 0 3 0.04 Comparative Example 2 3 4 3 0.30 Comparative Example 3 3 3.8 11 0.06 As can be seen from the above, the warm-sensing cut-hole liquid surface layer material prepared by this method has excellent liquid absorption performance and reverse osmosis performance, and has a continuous warming effect; by comparing Examples 1-4 with Comparative Example 1, it can be seen that the product with the addition of the warming agent inclusion compound has a warming effect of up to 4 hours; by comparing Examples 1-3 with Comparative Example 2, it can be seen that the product impregnated with the hydrophobic finishing agent solution has a reverse osmosis value reduced by 0.27g compared with the product not impregnated with the hydrophobic finishing agent solution, effectively blocking the reverse osmosis of water and improving water resistance; by comparing Examples 1-4 with Comparative Example 3, it can be seen that the absorption speed of the product with fine cut holes is increased by up to 8S compared with the product without fine cut hole treatment, showing excellent absorption rate improvement.

[0052] The above description is only a preferred embodiment of the present invention. Therefore, any equivalent changes or modifications made according to the structure, characteristics and principles described in the scope of the patent application of the present invention are included in the scope of the patent application of the present invention.

Claims

1. A method for preparing a thermally sensitive cutting hole liquid surface layer material, characterized in that: The following steps are involved: S1. Weigh a certain amount of polyurethane and dissolve it in an organic solvent to prepare a polyurethane solution; S2. The polyurethane solution obtained in step S1 and the emulsifier are added to an emulsifier and sheared at high speed to obtain a polyurethane emulsion; S3. A warming agent was prepared by inclusion of an inclusion agent to obtain a warming agent inclusion compound; S4. The warming agent inclusion compound prepared in step S3 is added together with the softener to the polyurethane emulsion prepared in step S2 and stirred thoroughly to obtain a uniform dispersion to obtain a mixed emulsion; S5. The mixed emulsion obtained in step S4 is sprayed on the surface of the non-woven fabric to obtain a nanofiber non-woven composite material; S6. The nanofiber nonwoven composite material is immersed in a hydrophobic finishing agent solution, fully impregnated, and then the excess solution is removed by roller extrusion and dried to obtain a hydrophobically modified nanofiber nonwoven composite material; S7. Cut holes in the hydrophobically modified nanofiber non-woven fabric composite material obtained in step S6 to obtain a warm-sensing hole-cut liquid surface layer material.

2. The method for thermally cutting a liquid surface layer material according to claim 1, characterized in that: The concentration of the polyurethane solution prepared in step S1 is 150-250 mg / ml.

3. The method for thermally cutting a liquid surface layer material according to claim 1, characterized in that: The emulsifier in step S2 is selected from one of a nonionic emulsifier and a cationic emulsifier, the weight ratio of the polyurethane solution to the emulsifier is 100:5-100:10, the high-speed shearing is 1200 revolutions per minute, and the shearing time is 30-45 minutes.

4. The method for thermally cutting a hole in a liquid surface layer material according to claim 1, characterized in that: The warming agent in step S3 is one of a vanillyl ether compound, an amide compound, vanillin acetal, gingerol or nicotinic acid tocopherol, the inclusion compound is one of a cyclodextrin or a cyclodextrin derivative or chitosan, the weight ratio of the warming agent to the cyclodextrin or cyclodextrin derivative inclusion agent is 1:1-1:8, and the weight ratio of the warming agent to the chitosan inclusion agent is 1:1-1:

3.

5. The method for thermally cutting a liquid surface material according to claim 4, characterized in that: The chitosan inclusion agent is modified chitosan, and the preparation method of the warming agent inclusion compound is as follows: dissolving ethylene glycol chitosan in an acetic acid buffer solution (pH=6), adding acetic anhydride to carry out an N-acetylation reaction, controlling the molar ratio of acetic anhydride to ethylene glycol chitosan amino groups to be 1.5:1-2.0:1 to obtain a modified chitosan solution, mixing the warming agent and the modified chitosan solution, using 300W power ultrasonic dispersion for 10 minutes, and heating to 37°C to obtain the warming agent inclusion compound.

6. The method for thermally cutting a liquid surface layer material according to claim 1, characterized in that: The weight ratio of the polyurethane emulsified solution prepared in step S2 to the warming agent inclusion compound prepared in step S3 and the softener is 100:20-30:

10.

7. The method for thermally cutting a hole in a liquid surface material according to claim 1, characterized in that: The mixed emulsion in step S5 is sprayed using an emulsion electrospinning device, the electrospinning voltage is 15-20 kV, the flow rate is 0.5-1.5 mL / h, and the receiving distance is 15-20 cm.

8. The method for thermally cutting a hole in a liquid surface layer material according to claim 1, characterized in that: The hydrophobic finishing agent in step S6 is one or more of amino silicone oil, hydroxyl-terminated polysiloxane, alkoxysilane, C6 short-chain fluoride, fluorine-free water-repellent finishing agent, calcium stearate, stearamide, acrylate copolymer, polyurethane-silicone block copolymer, silicone-fluorocarbon composite finishing agent, and nano-silica composite finishing agent. The mass-volume concentration of the hydrophobic finishing agent solution is 6.0-8.0 g / L, the immersion time is 0.1-5 min, and the nanofiber non-woven fabric composite material after removing excess solution by a pressing roller is dried at 80-150° C. for 10-15 min to obtain a hydrophobically modified nanofiber non-woven fabric composite material.

9. The method for thermally cutting a liquid surface material according to claim 1, characterized in that: The cutting process in step S7 is one of laser cutting, mechanical cutting, and ultrasonic cutting, and the hydrophobically modified nanofiber non-woven fabric composite material is precisely cut into regular holes. The preset cutting parameters are: the hole shape is a patterned design, the hole diameter is 1mm-8mm, and the hole spacing is 3-16mm.

10. Use of the heat-sensitive cut-hole liquid surface layer material prepared according to any one of claims 1 to 9 in sanitary products such as sanitary napkins, menstrual pants, incontinence napkins, incontinence pants, diapers, disposable underwear, and wound dressings.